6 Hit Points
Elemental Affinity - At character creation, select either fire, cold, lightning, or acid damage. You are immune to non-magical damage of that type, and make Saves against magical damage of that type at Advantage.
Dragonborn age very rapidly, walking only a few hours after birth and attaining the size and development of a 10-year-old human by the age of 3. They live around 80 years, on average.
They range from 5'5ft-7ft in height.
Dragons are ancient, powerful creatures long since thought to be nothing but myth and legend. The only thing that remained of their presence was the Dragonborn, those who held long ancestral draconic bloodlines. Their appearance is reptilian in nature, and their features vary a lot from lineage to lineage. Everything from scale color, horns, ears, hair, etc can change depending on the Dragonborn.
It's said that during this 'age of dragons' a long time ago, the dragons were able to harness the elements and use them to their advantage to take control over the land. Unfortunately, these abilities have been diluted to just basic resistance over time. However, what still remains true is that a Dragonborn's color does dictate their ancestral resistance.
Reds, oranges, yellows, and general warm colors - Fire
White, silver, grey, and light blues- Cold
Greens, browns, and teal - Acid
Purples, dark blues, blacks - Lightning
Dragonborn were varied in their lives, often assimilated into mundane cultures instead of clustering as their own individual people. Thus Dragonborn "culture" is not very well known. However, there are some quirks that are common among them, that often distinguish them as draconic in nature rather than just reptilian. Some of these quirks include:
Glowing eyes, typically corresponding around the element of their ancestry.
Horns, sometimes multiple sets, on their head or smaller ones running down their spine and tail.
An almost instinctual possessiveness, likely gained from the mythos of Dragons being hoarders.
Very strong intellectual knowledge, as dragons were once quite wise.
You can choose one or more of these traits, or make up your own that fits your character.